the act of omitting.

the state of being omitted.

something left out, not done, or neglected

an important omission in a report.

noun

addition , inclusion , insertion , remembrance

noun

blank , breach , break , cancellation , carelessness , chasm , cutting out , default , disregard , disregardance , elimination , elision , excluding , exclusion , failing , failure , forgetfulness , gap , hiatus , ignoring , inadvertence , inadvertency , lack , lacuna , lapse , leaving out , missing , neglect , noninclusion , overlook , overlooking , oversight , passing over , preclusion , preterition , pretermission , prohibition , repudiation , skip , slighting , slip , withholding , delinquency , dereliction , aphaeresis , aphesis , apocope , ellipsis , error , haplology , misfeasance , negligence , non-performance , omittance , paralipomena , paralipsis , syncope